Given that I’m leaving tomorrow for the Canadian Rockies, I’ve been inspired to look through some of my photos from last summer, and to realize how few of them I’ve blogged so far. So let me show you some folded things today that Lily and I saw the afternoon we arrived at Waterton Lakes National … Read more
This week, the Friday fold comes to us courtesy of fellow AGU-hosted geoblogger Jessica Ball: That’s chert cropping out in Golden Gate Park, San Francisco. Maybe you should check it out in December when you’re in the Bay area for the AGU Fall Meeting? Outcrop location: Lat/Long: 37.771517,-122.4777. Annotated version: Recall there are more chert … Read more
Another landform seen out the window of that very productive photo-flight last March: That’s a breached plunging anticline – doubtless a Laramide structure. This was over Wyoming; I think here. Looking north-ish, along the axis of the fold: Note that the lengths of section line A and B are not equal: this anticline is asymmetric. … Read more
Today’s fold comes to us from the Alps, courtesy of blog reader “Earth Mama.” She says: Attached is a photo of the outcrop, near Brienz, Switzerland, and a GE screenshot of the location. I saw this as I was looking out the train window, and was able to grab my camera in time. Best I … Read more
Another guest submission for the Friday fold – this is becoming a major trend! Peter Selkin‘s student Rick Schwartz loaned us this one. Peter describes the outcrop this way: The rocks here are Miocene turbidites of the Hoh lithic assemblage (sometimes called the “Hoh Terrane”) exposed at Beach #4 on the Pacific coast of the … Read more
The Friday fold “guest fold” series continues with a folded ultramylonite from South Africa.
Another guest submission for the Friday fold: Callan – Please find enclosed a collection of photos you could possibly use for a future Friday Fold blog post. The following photos were all taken by me on Sunday, April 29th, in the vicinity of Bedford Peak and the Maple Springs Trailhead (Silverado Canyon Road), Cleveland National … Read more
Max Arndt contributed this week’s Friday fold: (click on the image to get to a larger sized version on Max’s Flickr page) That’s the Warah Formation exposed on the Batain Coast of northeastern Oman. This is the thrust front of a thin-skinned fold and thrust belt. I think it’s just lovely! Max has a ton … Read more
Another guest Friday fold – this one supplied by Ander Sundell of the College of Western Idaho, and his student Katie Ursenbach, who took the shot and gave permission for me to re-post it here. You’re looking at cuspate-lobate folds due to primary sedimentary settling. the Snake River Canyon in southwestern Idaho. A pile of … Read more
The Friday fold is a contribution from the Massachusetts Geological Survey. It shows a migmatite with lovely structure. An upcoming (free) field trip to this location will be part of the 2012 Structural Geology and Tectonics Forum: an event readers may be interested in attending
I got this note via email last week. Hi Callan, First of all, congratulations to your blog. It is just great. I would like to contribute to your “Friday fold” section. A few words about myself. I am born in Austria and did my BSc and MSc at the Montanuniversitaet Leoben. In September 2011 I started … Read more
Rob Simmon of NASA’s Earth Observatory is the source for today’s Friday folds. Last week, he tweeted this image to me: That’s a excellent example of the outcrop pattern of a more or less horizontal outcrop of folded rock. To the north is a synform (notice that where streams have eroded it, the bull’s-eye pattern … Read more
I got an email a few weeks back from Moritz K., a PhD student at the Universidad Nacional Autónoma de México (UNAM) in Querétaro. He wanted to offer up a potential Friday fold. Here’s what he had to say: I wanted to send you a couple of pictures of folds I took in my PhD … Read more
Richard Littauer, a MSc student in Computational Linguistics at the University of Saarland (on Twitter at @richlitt) sent me today’s Friday fold. It comes from a garden at Nijo Castle in Kyoto, Japan. Definitely some wavy layers there. It’s a lovely specimen that would add gravitas to anyone’s garden. Not sure what it is – … Read more
Searching for Peter Luffi’s latest Where On Google Earth? challenge, I found myself touring Iceland last week. While I didn’t find the strange comet-shaped feature he posted, I did find this: And zooming in a bit, to the high-contrast area in the center: This appears to be volcanic ash layers distorted by glacial flow and … Read more
Hand sample of folded limestone strata in West Virginia (presumably Devonian in age). Note the rip-up clasts and large grain size at the base of the sample (to the right in the photo). Note the fine-grained, thin-bedded shale laminations towards the top (left) of the sample, too. Together, they tell a story of decreasing energy … Read more
Callan and his field studies students encounter a lesson in the White Mountains of eastern California that combines bedding, cleavage, folding, and even fossil archaeocyathids!
While on Callan’s field course in eastern California, student Filip finds a lovely fold sample.
Meter-scale fold in metagraywacke layers at the head of Mather Gorge, Maryland shore of the Potomac River, highlighted by differential weathering along the layering. Annotated interpretation: Happy Friday!
GigaPan by Alan Pitts, as part of the M.A.G.I.C. project that we are working on. Here’s another one from a few meters away. Here’s a shot from 2.5 minutes after Alan saw this anticline for the first time. Here’s some shots of my own early visit to the site, after I first found it.